Sam Asghari was surprised by wrestler-turned-actor John Cena on their action film Jackpot!, quickly bonding with the whipsmart entertainer off-camera. “We really just talked about acting [as well as] cars, watches and food,” Asghari, 30, exclusively told Us Weekly on Wednesday, July 31. “It’s a really cool experience to get to know someone like that, and he’s a super humble …